In order to realize numerical control transformation and application of SJJF digital display manual indexing head with highaccuracy, meet practical requirements of automatic calibration and detection of angular displacement sensor used in an aeroengine performance test bench, and solve the time-consuming and labor-intensive problem of manual angle indexing, a design scheme for automatic angle indexing control system is proposed. It uses a programmable logic controller (PLC) in conjunction with a special ladder diagram programming command torealize automatic digital acquisition of angle grating signal, angle value conversion, proportion integration differentiation (PID) control positioning and grating zeroing, which can effectively meet calibration accuracy requirements such as linearity and sensitivity of the angular displacement sensor for platform, save 70% of original manual calibration time, improve angle indexing efficiency and reduce labor intensity.